The invention relates to an electrically controlled fuel injection apparatus of the type described in the Schwartz et al. application Ser. No. 963,711 filed Nov. 27, 1978, now U.S. Pat. No. 4,197,823. Such an apparatus is already known which has a temperature sensor which measures the coolant or cylinder head temperature for the purpose of controlling the enrichment of the fuel-air mixture during the warm-up phase of the internal combustion engine and in which the time control of the enrichment is carried out electronically. In order to increase the mixture quantity in this apparatus, a supplementary air valve is provided within a lateral channel which bypasses the throttle valve in the intake manifold. This supplementary air valve has a movable valve member which more or less widely opens the cross-sectional area of the lateral channel and is actuatable by means of a bimetallic spring against a return force. An electric heating device is attached at least partially to the bimetallic spring with this device being arranged to be switched on with the ignition of the internal combustion engine.